The former Wimbledon champion said his serve is now so weak that he would struggle to beat the Williams sisters.
The 36-year-old American barely broke sweat in a one-sided first set but was tested by the world number 135 in the second without ever looking troubled.
Six-time champion Roger Federer produced a vintage display to beat defending champion Novak Djokovic 6-3, 3-6, 6-4, 6-3 in the Wimbledon semi-final on Friday.
Federer, a 20-times Grand Slam champion and regarded as one of the greatest players of all time, announced last week that a persistent knee injury meant he was ending his 24-year career.
The 20-year-old Spaniard will attempt to end Djokovic's 34-match winning run on the Wimbledon grass.
Venus Williams targets return for Indian Wells and Miami
Wimbledon champion Andy Murray has split with coach Ivan Lendl after two years, the British world number six said on Wednesday.
Maria Sharapova will probably have to win 10 matches to claim a second Wimbledon title this year after deciding on Friday not to request a wildcard for the championships.
Former world number one Maria Sharapova has been handed a wildcard to the Wimbledon warm-up tournament in Birmingham in June.
Factbox on Belarus' Aryna Sabalenka, who beat China's Zheng Qinwen in the Australian Open final on Saturday
Sumit Nagal entered the history books as only sixth Indian to win a Grand Slam junior title after winning the boys doubles trophy at the Wimbledon Championships with partner Nam Hoang Ly on Sunday.
Spain's World Cup winning midfielder Aitana Bonmati was named the Sportswoman of the Year, while Serbia's Novak Djokovic captured the top men's honour at the Laureus awards ceremony on Monday.
Naomi Osaka emerged as a fresh champion at Melbourne Park as well as the new World No 1 on Saturday.
The German fifth seed kicks off her campaign against compatriot Tatjana Maria on Tuesday, but could potentially face three former champions in Serena Williams, Garbine Muguruza and Maria Sharapova if she goes deep into the tournament.
Check out the most shocking upsets at this year's Wimbledon.
Check out some of the up-and-comers who could cause an upset at Wimbledon this year.
Former Romanian world number one Ilie Nastase called Wimbledon organisers "small-minded" after they announced he would not be invited to the Royal Box at this year's championships.
Elena Rybakina knocked out defending champion Iga Swiatek at Indian Wells on Friday to set up a clash against Aryna Sabalenka in the final.
Rewarding as it was for Rafael Nadal to become the only player to win the same Grand Slam 12 times by chalking up his dozen at last month's French Open, the Spaniard arrived at Wimbledon this year like a man on a mission. In the end, however, it became mission impossible as he lost to inspired Roger Federer in Friday's blockbuster semi-final.
Petra Kvitova's preparations for the defence of her Wimbledon title suffered a setback when she was beaten by Russia's Ekaterina Makarova in the first round of the Eastbourne International on Tuesday.
A look at the winners of the various titles at Wimbledon 2009.
Venus Williams ended Johanna Konta's fairy tale run 6-4, 6-2 to reach her first Wimbledon singles final since 2009.
'Yes, I fall over, but grass sometimes is slippery. Nothing happens. I am good, yeah. Nothing'
Novak Djokovic and Serena Williams are top seeds at the major starting Monday
Three-times winner Serena Williams moved into the Toronto Open second round after beating Spain's Nuria Parrizas Diaz on Monday
The eight seeded South African fought back after losing the first two sets to defeat the Swiss ace 2-6, 6-7(5), 7-5, 6-4, 13-11.
As the event goes into its second week, only six of the men's top 16 seeds and eight of the women's have made it through to the fourth round.
Two-time winner Petra Kvitova and world number three Karolina Pliskova will be tough to beat at Wimbledon because the tournament's grass courts suit their games down to the ground, Serena Williams' coach Patrick Mouratoglou has said.
Frenchman Gael Monfils has withdrawn from Wimbledon with a shoulder injury, tournament organisers said on Monday.
Angelique Kerber is looking forward to a potential German sporting double over the next fortnight, aiming to win Wimbledon as one of the favourites while also cheering on her national football team at Euro 2016. Australian Open champion Kerber revealed on Saturday that she had been hooked on watching the Euros, particularly the progress of Die Mannschaft, during her preparations in London.
Novak Djokovic has lost his aura of invincibility but coach Andre Agassi says nobody should be surprised if the Serb goes on to claim his fourth Wimbledon title this month.
Wozniacki battles past Kerber into Eastbourne final
Italy's Matteo Arnaldi produced a sensational performance to take out sixth seed Andrey Rublev and reach the last 16 of the French Open on Friday.
Andy Murray needs to ditch the 'Mr Nice Guy' image and become more arrogant, brash and big-headed if he has aspirations of becoming Wimbledon champion, according to Goran Ivanisevic.
It was job well done for Novak Djokovic as he silenced Bernard Tomic and his Australian Fanatics with an emphatic 6-3, 6-3, 6-3 victory in the Wimbledon third round on Friday.
Images from Friday's matches at Wimbledon.
IMAGES from the matches played on Day 4 of the Wimbledon Lawn Tennis Championships at All England Lawn Tennis and Croquet Club on Thursday
Wimbledon debutant Eubanks ends Tsitsipas's challenge in fourth round.
